Radiation detector

ABSTRACT

A radiation detector having a head and a main body. The head has a probe and a first articulation. The probe contains a radiation detection element, and is movable due to the first articulation. Separately from the first articulation, a second articulation is provided on the main body or the head or therebetween. Accordingly, the radiation detector can move in a different way that allowed for by the first articulation. Combining the motion by the first articulation with the motion by the second articulation increases flexibility of handling the radiation detector. Hence the radiation detector has improved ease of operation.

TECHNICAL FIELD

The present invention relates to a radiation detector, and, for example,to a radiation detector for detecting radioactive material existing inthe tissue of a body.

BACKGROUND ART

In a test for metastasis of cancer, it has been carried out toadminister radioactive medicine into a body and detect radioactivematerial agglomerated in the tissue of the body, thereby specifying theposition of the tissue to which the cancer metastasizes. An example of aradiation detector used to detect radioactive material is described inU.S. Pat. No. 6,236,880 B1. This radiation detector is of a hand heldtype. In this radiation detector, a curved tube is connected to thedistal end of the main body, and various probe distal ends can bemounted on the distal end of the tube. A radiation detection element isbuilt into each probe distal end.

In the field of the radiation detector, a radiation detector which iseasier to handle has been required to quickly detect radioactivematerial in a body.

DISCLOSURE OF THE INVENTION

It is an object of the invention to improve ease of operation of theradiation detector.

The radiation detector according to the present invention has a mainbody, and a head connected to an end of the main body. The main body hasa grip. The head has a probe and a first articulation. The probecontains a radiation detection element. The first articulation isconnected to the probe. For example, the radiation detection element maybe disposed at the distal end of the probe, and the first articulationmay be connected to the proximal end of the probe. The firstarticulation enables the probe to move. A second articulation isprovided to the main body or the head or between the main body and thehead. This enables the radiation detector to move in different ways thatallowed for by the first articulation. The second articulation mayenable the head to move with respect to the grip. Combining the motionbased on the first articulation with the motion based on the secondarticulation increases flexibility of handing the radiation detector.Hence the radiation detector according to the present invention hasimproved ease of operation.

The present invention can be sufficiently understood from the followingdetailed description and accompanying drawings. The accompanyingdrawings are merely examples, and thus it should be noted that theaccompanying drawings do not limit the present invention.

A further application field of the present invention will be clear fromthe following detailed description. However, the detailed descriptionand specific examples show the preferred embodiments of the presentinvention, however, they are merely examples. Various modifications andalterations within the purpose and scope of the present invention willbe apparent by persons skilled in the art from the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A and FIG. 1B are a plan view and a side view generally showing aradiation detector according to a first embodiment.

FIG. 2 is an exploded partial cross-sectional view showing the structureof a head.

FIG. 3 is an exploded view showing the structure of a main body.

FIG. 4 is an exploded perspective view showing a moving mechanism of anintermediate portion.

FIG. 5 is a perspective view showing the motion of the radiationdetector.

FIG. 6A and FIG. 6B are perspective views showing the motion of aradiation detector according to a second embodiment.

FIG. 7 is an exploded partial cross-sectional view showing the structureof the head and articulation of the radiation detector.

FIG. 8 is an exploded perspective view showing the structure of thearticulation of the radiation detector.

FIG. 9 is a cross-sectional view showing the head and articulation ofthe radiation detector.

FIG. 10 is a perspective view showing the motion of a radiation detectoraccording to a third embodiment.

FIG. 11 is a perspective view showing the motion of a radiation detectoraccording to a fourth embodiment.

FIG. 12 is a perspective view showing a radiation detector according toa fifth embodiment.

FIG. 13 is a perspective view showing a radiation detector according toa sixth embodiment.

FIG. 14 is a perspective view showing the structure of a ball joint typearticulation.

BEST MODES FOR CARRYING OUT THE INVENTION

Embodiments according to the present invention will be described indetail with reference to the accompanying drawings. In the descriptionof the drawings, the same elements are represented by the same referencenumerals and overlapping description is omitted.

First Embodiment

FIGS. 1A and 1B are a plan view and a side view generally showing aradiation detector 1 according to a first embodiment. The radiationdetector 1 is a wireless and hand held type detector. The radiationdetector 1 has a head 2 and a main body 3. The head 2 is provided withan articulation 4. The main body 3 is provided with an articulation 5.

The head 2 has a probe 20 and a base 21. The probe 20 is disposed at thedistal end of the radiation detector 1. The proximal end of the probe 20is connected to the distal end of the base 21. The proximal end of thebase 21 is connected to the distal end of the main body 3. The base 21constitutes the articulation 4. The articulation 4 enables the probe 20to swing. The base 21 has a probe fixing member 210 and holding members211 and 212. The probe 20 is fixed to the probe fixing member 210. Theprobe fixing member 210 is held between the holding members 211 and 212so as to be able to swing.

The main body 3 has a grip 32 and an intermediate portion 310 sandwichedbetween the grip 32 and the head 2. The distal end of the intermediateportion 310 is connected to the holding members 211 and 212. Theproximal end of the intermediate portion 310 is connected to the grip 32via the articulation 5.

The intermediate portion 310 is provided with a display section 315. Thedisplay section 315 has a display screen 315 a and an LED group 315 b. Ameasurement value of radiation detection is displayed on the displayscreen 315. The LED group 315 b is turned on in accordance with theoperation state of the radiation detector 1 and the residual quantity ofa battery. The display section 315 may be provided to the grip 32. Thedisplay section 315 may show the measurement value with a Beep sound, aWave sound or a voice readout of a count value. These sounds arereproduced from a speaker 326, and the speaker 326 is disposed at theproximal end of the grip 32.

A joint 310 a is provided to the proximal end of the intermediateportion 310. The joint 310 a is sandwiched by the holding members 311and 312 so as to be able to swing. The joint 310 a and the holdingmembers 311 and 312 constitute the articulation 5. The articulation 5enables the intermediate portion 310 to swing with respect to the grip32. The holding members 311 and 312 are connected to the grip 32. Thegrip 32 is designed in such a shape that the user can easily grasp thegrip 32. The grip 32 is provided with an ON/OFF switch 321. The user canturn the radiation detector 1 on and off by pressing the switch 321.

Referring to FIG. 1B, a control circuit 316 is disposed in theintermediate portion 310. The control circuit 316 includes a signalamplifying circuit, a voltage step up device for the voltage applied toa radiation detection element, etc. The display screen 315 a and the LEDgroup 315 b are placed above the control circuit 316. Transparent windowportions 315 c and 315 d are provided above the display screen 315 a andthe LED group 315 b. The window portions 315 c and 315 d are disposed inthe side wall of the intermediate portion 310.

A switching circuit 322 and a power source section 323 are provided inthe grip 32. The switching circuit 322 is electrically connected to theswitch 321. The switching circuit 322 is electrically connected to thecontrol circuit 316 by a cable 330. The cable 330 is, for example, amulti-axial cable or flat cable. A battery is disposed in the powersource section 323. The power source section 323 is electricallyconnected to the switching circuit 322. The switching circuit 322supplies power from the power source section 323 to the control circuit316 or stops the power supply in response to pressing the switch 321.However, a section which is required to be supplied with power at alltimes, for example, CPU for recognizing ON/OFF of the switch 321 issupplied with power irrespective of ON/OFF of the switch 321. Whensupplied with power, the control circuit 316 turns on a predeterminedLED of the LED group 315 b, and drives the display screen 315 a.

When using the radiation detector 1, the user grasps the grip 32, turnsthe switch 321 on, and then aims the head 2 at an object to be examined.The detection result is displayed on the display screen 315 a.

The structure of the radiation detector 1 will be described in detailwith reference to FIGS. 2 to 4. FIG. 2 is an exploded partialcross-sectional view mainly showing the structure of the head 2. FIG. 3is an exploded view showing the structure of the main body 3. FIG. 4 isan exploded perspective view showing a moving mechanism of theintermediate portion 310.

First, the structure of the probe 20 will be described. The probe 20 hasa probe cover 201, a side shield 202 and a radiation detection element203. These elements have axially symmetrical shapes, respectively.

The probe cover 201 has a substantially cylindrical shape. A radiationincident window 205 is disposed at the distal end of the probe cover201. The side shield 202 is accommodated and fixed in the hollow portion201 a of the cover 201 so as to coaxially extend along the center axis 7of the cover 201. The side shield 202 has a substantially cylindricalshape. A semiconductor radiation detection element 203 is accommodatedin the hollow portion 202 a of the side shield 202. The radiationdetection element 203 is accommodated in a substantially cylindricalelement case 203 a. The element 203 has a detection face 203 b forreceiving radiation. The detection face 203 b is located at the distalend of the element case 203 a. The element 203 generates an electricaloutput in response to incidence of radiation on the detection face 203a. The element case 203 a is inserted in the hollow portion 202 a of theside shield 202 coaxially along the axis 7, and fixed therein. The sideshield 202 blocks off the radiation coming from the side of the detector1 that originates from the portions other than the detection portion ofthe object to be examined and results in causing detection noise,thereby enhancing the detection precision.

An elongated and cylindrical-shaped collimating opening 206communicating with the hollow portion 201 a is further provided on thedistal end of the probe cover 201. The cross section area perpendicularto the axis 7 of the collimating opening 206 is set to be smaller thanthose of the hollow portion 201 a and the element case 203 a. Thecollimating opening 206 extends from the back side of the window 205 tothe detection face 203 b of the element 203. The collimating opening 206collimates the radiation transmitted through the window 205. This blocksoff the radiation coming from the side of the detector 1 that originatesfrom the portions other than the detection portion of the object to beexamined and causes the detection noise, and thereby enhancing thedetection precision.

The structure of the base 21 will now be described. As described above,the base 21 consists of the probe fixing member 210 and the holdingmembers 211 and 212. The holding members 211 and 212 holding the probefixing member 210 therebetween so that the probe fixing member 210 isable to swing.

The probe fixing member 210 has a main body 210 a extending along theaxis 8, and a protrusion 210 b extending along a direction perpendicularto the axis 8. The main body 210 a is provided with a through hole 210 cextending along the axis 8. The through hole 210 c is designed to besubstantially circular in section. The protrusion 210 b is provided witha through hole 210 d extending along a direction perpendicular to theaxis 8. The through holes 210 c and 210 d communicate with each other. Afemale screw is formed in the inner surface of the protrusion 210 b.

The holding member 211 has an insertion portion 211 a which extendsalong the axis 8 and has a substantially cylindrical shape. An O ring213 is mounted on the outer surface of the insertion portion 211 a. Theinsertion portion 211 a and the O ring 213 is inserted in one of the endportions of the through hole 210 c of the probe fixing member 210. As aresult, the O ring 213 is sandwiched between the inner surface of theprobe fixing member 210 and the outer surface of the insertion portion211 a. A screw hole 246 is provided on the rear end face of the holdingmember 211. The holding member 211 is provided with a through hole 211 bfor wiring.

As in the case of the holding member 211, the holding member 212 has aninsertion portion 212 a. The insertion portion 212 a extends along theaxis 8, and has a substantially cylindrical shape. An O ring 214 ismounted on the outer surface of the insertion portion 212 a. Theinsertion portion 212 a and the O ring 214 are inserted in the endportion of the through hole 210 c of the probe fixing member 210 at theopposite side to the holding member 211. As a result, the O ring 214 issandwiched between the inner surface of the probe fixing member 210 andthe outer surface of the insertion portion 212 a. A screw hole 247 isprovided on the rear end face of the holding member 212.

As described above, the holding members 211 and 212 hold the probefixing member 210 therebetween via the O rings 213 and 214, therebysealing the articulation 4. The O rings 213 and 214 are slidably incontact with the inner surface of the probe fixing member 210.Accordingly, the probe fixing member 210 is able to swing around theaxis 8 with respect to the holding members 211 and 212. The insertionportions 211 a and 212 a form a swing shaft.

The probe 20 is fixed to the probe fixing member 210 by using aconnection pipe screw 220. A male screw 220 a is formed on the outersurface of the connection pipe screw 220. The male screw 220 a isengaged with the female screw formed on the inner surface of theprotrusion 210 b of the probe fixing member 210. A sealing O ring 222 ismounted on the surface of the distal end portion of the connection pipescrew 220.

The distal end portion of the connection pipe screw 220 is inserted inthe probe cover 201 along the axis 7. As a result, the O ring 222 issandwiched between the inner surface of the probe cover 201 and theouter surface of the connection pipe screw 220, thereby sealing theprobe 20. The distal end portion of the connection pipe screw 220 islocated behind the side shield 202 and the radiation detection element203 in the probe 20.

When the connection pipe screw 220 is inserted in the probe cover 201,the screw-provided rear end portion of the connection pipe screw 220 isprojected from the probe cover 201. Therefore, by screwing thescrew-provided rear end portion into the protrusion 210 b of the probefixing member 210, the probe 20 can be fixed to the probe fixing member210. When the probe 20 is fixed to the probe fixing member 210, the axis7 and the axis 8 are perpendicular to each other. Since the probe fixingmember 210 is able to swing, the probe 20 is able to swing around theaxis 8. As described above, the base 21 acts as the articulation 4 forenabling the probe 20 to move.

Lead wires 231 and 232 are bonded to the radiation detection element203. The lead wires 231 and 232 are connected to the control circuit316. The output of the radiation detection element 203 is transmitted tothe control circuit 316 through these lead wires. The lead wires 231 and232 pass through the hollow portion of the connection pipe screw 220,the through holes 210 d and 210 c of the probe fixing member 210 and thethrough hole 211 b of the holding member 211.

A support plate 318 is fixed to the rear end of the base 21 usingscrews. Two holes are formed in the support plate 318 so as to penetratethrough the support plate 318. The screws 241 and 242 are inserted inthese holes. The distal ends of the screws 241 and 242 project from thesupport plate 318. Sealing O rings 248 and 249 are mounted on the distalends of the screws 241 and 242. These distal ends are screwed into thescrew holes 246 and 247 of the holding members 211 and 212 respectively,whereby the support plate 318 is fixed to the rear end surfaces of theholding members 211 and 212.

The support plate 318 is designed in such a shape that two flat platesdifferent in area are coaxially overlapped with each other. An O ring319 is mounted on the outer periphery of the flat plate having thesmaller area. The support plate 318 is accommodated in the intermediateportion 310. The O ring 319 is sandwiched between the inner surface ofthe intermediate portion 310 and the outer peripheral surface of thesupport plate 318, thereby sealing the intermediate portion 310.

In addition to the through hole for the screw, a through hole for wiringis provided in the support plate 318. The lead wires 231 and 232 passthrough the hole for wiring, and extend to the control circuit 316 inthe intermediate portion 310. The wiring hole of the support plate 318face the through hole 211 b of the holding member 211. A sealing O ring233 is disposed between the wiring hole and the through hole 211 b.

The structures of the intermediate portion 310 and the articulation 5will now be described with reference to FIG. 3 and FIG. 4. Thearticulation 5 consists of the joint 310 a of the intermediate portionand the holding members 311 and 312. The holding members 311 and 312hold the intermediate portion 310 therebetween so that the intermediateportion 310 is able to swing.

The distal end of the intermediate portion 310 is connected to the head2 through the support plate 318. The joint 310 a is integrally providedto the rear end of the intermediate portion 310. The joint 310 a isprovided with a through hole 310 b. The joint 310 a is held between theholding members 311 and 312.

The holding member 311 has an insertion portion 311 a. The insertionportion 311 a extends along the axis 9, and has a substantiallycylindrical shape. An O ring 313 is mounted on the outer surface of theinsertion portion 311 a. The insertion portion 311 a and the O ring 313are inserted in an end portion of the through hole 310 b of the joint310 a. As a result, the O ring 313 is sandwiched between the innersurface of the joint 310 a and the outer surface of the insertionportion 311 a. A screw hole 256 is provided on the rear end surface ofthe holding member 311. The holding member 311 is provided with athrough hole 311 b for wiring.

As in the case of the holding member 311, the holding member 312 has aninsertion portion 312 a. The insertion portion 312 a extends along theaxis 9, and has a substantially cylindrical shape. An O ring 314 ismounted on the outer surface of the insertion portion 312 a. Theinsertion portion 312 a and the O ring 314 are inserted in the endportion of the through hole 310 b of the joint 310 a at the oppositeside to the holding member 311. As a result, the O ring 314 issandwiched between the inner surface of the joint 310 a and the outersurface of the insertion portion 312 a. A screw hole 257 is provided inthe rear end surface of the holding member 312.

As described above, the holding members 311 and 312 hold the joint 310 aof the intermediate portion 310 therebetween through the O rings 313 and314, thereby sealing the articulation 5 and the intermediate portion310. Furthermore, the O rings 313 and 314 are slidably in contact withthe inner surface of the joint 310 a. Therefore, the intermediateportion 310 is able to swing around the axis 9 with respect to theholding members 311 and 312. The insertion portions 311 a and 312 a forma swing shaft.

An end of the cable 330 for wiring is electrically connected to thecontrol circuit 316. The other end of the cable 330 is connected to theswitch circuit 322 in the grip 32. The operating power of the controlcircuit 316 is supplied via the cable 330. The cable 330 passes throughthe hollow portion of the intermediate portion 310, the through hole 310b of the joint 310 a and the through hole 311 b of the holding member311.

The support plate 328 is fixed to the proximal end of the articulation 5using screws. Two holes penetrating through the support plate 328 areformed in the support plate 328. The screws 251 and 252 are inserted inthese holes. The distal ends of the screws 251 and 252 project from thesupport plate 328. These distal ends are screwed in the screw holes 256and 257 of the holding members 311 and 312, whereby the support plate328 is fixed to the rear end surfaces of the holding members 311 and312.

The support plate 328 has such a shape that two flat plates different inarea are coaxially overlapped with each other. An O ring 329 is mountedon the outer periphery of the flat plate having the smaller area. Thesupport plate 328 is accommodated in the grip 32. The O ring 329 issandwiched between the inner surface of the grip 32 and the outerperipheral surface of the support plate 328, thereby sealing the grip32.

A through hole for wiring is formed in the support plate 328 in additionto the screw holes. The cable 330 passes through the through hole andextends to the switch circuit 322 in the grip 32.

The advantages of this embodiment will now be described with referenceto FIG. 5. FIG. 5 is a perspective view showing the motion of theradiation detector 1. The radiation detector 1 has the two articulations4 and 5, and thus it is movable at the two positions. Hence theradiation detector 1 has improved ease of operation. With respect to theswing motion of the probe 20 through the articulation 4, the angle ofthe probe 20 is adjustable with respect to the intermediate portion 310.Furthermore, with respect to the swing motion of the intermediateportion 310 through the articulation 5, the angle of the intermediateportion 310 is adjustable with respect to the grip 32. Not only theangle of the probe 20, but also the angle of the intermediate portion310 can be adjusted, so that the probe 20 can be easily aimed at desiredplaces to be examined. Thus, according to the radiation detector 1,radiation can be quickly detected.

Second Embodiment

A radiation detector 1 a according to a second embodiment will now bedescribed. FIGS. 6A and 6B are perspective views showing the motion ofthe radiation detector 1 a. As shown in FIG. 6A, the radiation detector1 a has an articulation 6 provided between the head 2 and the main body3 in addition to the articulation 4 provided on the head 2. As shown inFIG. 6B, the articulation 6 enables the head 2 to rotate with respect tothe main body 3. The head 2 is rotatable around an axis 7 a. Not onlycan the angle of the probe 20 be adjusted by the articulation 4, butalso the head 2 can be rotated by the articulation 6, so that theradiation detector 1 a has excellent ease of operation. Consequently,the probe 20 can be easily aimed at desired places to be examined toquickly detect the radiation.

The structure of-the articulation 6 will now be described in detail withreference to FIGS. 7 to 9. FIG. 7 is an exploded partial cross-sectionalview showing the structures of the head 2 and the articulation 6. FIG. 8is an exploded perspective view showing the structure of thearticulation 6, and FIG. 9 is a cross-sectional view showing the head 2and the articulation 6. The structure of the head 2 is the same as thefirst embodiment, and the description thereof is omitted.

The articulation 6 has a head supporting member 601, a sleeve 602 and amain body fixing member 603. Assembling these elements enables thesleeve 602 and the main body fixing member 603 to rotate with respect toeach other.

The head supporting member 601 has a disc-shaped bottom wall and acylindrical side wall extending vertically from the bottom wall. Acylindrical shaft 601 a extends from the center of the bottom wallvertically with respect to the bottom wall. The shaft 601 a is longerthan the side wall of the head supporting member 601. Two holespenetrating through the head supporting member are formed in the headsupporting member 601. Screws 241 and 242 are inserted in these holes.The distal ends of the screws 241 and 242 project from the bottomsurface of the head supporting member 601. These distal end ends arescrewed in the screw holes 246 and 247 of the holding members 211 and212, whereby the head supporting member 601 is fixed to the rear endsurfaces of the holding members 211 and 212. At this time, the centeraxis of the shaft 601 a is substantially coincident with the center axis7 of the probe 20. The head supporting member 601 has a through hole 601b for wiring. The hole 601 b penetrates through the bottom wall and theshaft 601 a. Lead wires 231 and 232 bonded to the radiation detectionelement 203 pass through the through hole 601 b.

The sleeve 602 is slidably mounted on the head supporting member 601.The sleeve 602 is fitted inside the side wall of the head supportingmember 601. The sleeve 602 has a disc-shaped bottom wall, and a supportshaft portion 602 a extending vertically from the center of the bottomwall. A male screw is formed in the outer surface of the support shaftportion 602 a along the peripheral direction thereof. The sleeve 602 hasa hole 602 b penetrating through the bottom wall and the support shaftportion 602 a. When the sleeve 602 is fitted in the head supportingmember 601, the shaft 601 a of the head supporting member 601 isinserted in the hole 602 b. Correspondingly, the distal end of the shaft601 a is projected from the support shaft portion 602 a.

The main body fixing member 603 has a substantially disc-shaped upperwall and a cylindrical side wall extending vertically from the upperwall. The main body fixing member 603 has an opening portion 603 a foraccommodating the shaft supporting portion 602 a of the sleeve 602. Afemale screw is formed along the peripheral direction in the sidesurface of the opening portion 603 a. When the shaft supporting portion602 a is screwed in the opening portion 603 a, the male screw of theshaft supporting portion 602 a is engaged with the female screw of theopening portion 603 a, whereby the sleeve 602 and the main body fixingmember 603 are joined to each other. A through hole 603 c is formed inthe upper wall of the main body fixing member 603. The distal end of theshaft 601 a projecting from the shaft supporting portion 602 a isinserted in the through hole 603 c.

As shown in FIG. 9, an O ring 604 is mounted on the shaft 601 a. The Oring 604 is sandwiched between the upper end of the shaft supportingportion 602 a and the upper wall of the main body fixing member 603while it is in close contact with the surface of the shaft 601 a,thereby sealing the articulation 6.

An annular recess portion 603 d in which an O ring 605 is mounted isprovided on the periphery of the upper wall of the main body fixingmember 603. The annular recess portion 603 d is accommodated in theintermediate portion 310. The O ring 605 is sandwiched between the innersurface of the intermediate portion 310 and the outer surface of themain body fixing member 603, thereby sealing the intermediate portion310.

With the above structure, the head supporting member 601 can rotaterelatively to the sleeve 602 and the main body fixing member 603 usingthe shaft 601 a as a rotating shaft. The head 2 is fixed to the headsupporting member 601, and thus the head 2 can be rotated. Therotational axis 7 a is perpendicular to the swing axis 8 of the probe20.

Third Embodiment

A radiation detector 1 b according to a third embodiment will now bedescribed with reference to FIG. 10. FIG. 10 is a perspective viewshowing the motion of the radiation detector 1 b. As shown in FIG. 10,the radiation detector 1 b has the articulation 5 provided on the mainbody 3 and the articulation 6 provided between the head 2 and the mainbody 3 in addition to the articulation 4 provided on the head 2. Thestructures of these articulations have been already described above.

The radiation detector 1 is able to move at the three positions, andthus the ease of operation thereof is further improved. Flexibility ofadjusting the orientation of the probe 20 is very high, so that theprobe 20 can be easily aimed at the desired place to be examined toquickly detect the radiation.

Fourth Embodiment

A radiation detector 1 c according to a fourth embodiment will now bedescribed with reference to FIG. 11. FIG. 11 is a perspective viewshowing the motion of the radiation detector 1 c. The radiation detector1 c has two articulations 6 a and 6 b in addition to the articulations 4and 5. The articulation 6 a is provided between the head 2 and the mainbody 3. The articulation 6 b is provided on the intermediate portion310. The display section 315 is located between the articulation 6 a andthe articulation 6 b. Each of these articulations 6 a and 6 b is arotating mechanism having the same structure as the articulation 6 ofthe second embodiment. Thus the articulation 6 a enables the head 2 torotate around the axis 7 a. The articulation 6 b enables the displaysection 315 to rotate around the axis 7 a. The display section 315sandwiched between the articulations 6 a and 6 b can be rotatedindependently of the head 2. Therefore, the user can adjust theorientation of the display section 315 solely to set the display section315 easily visible. Therefore, when adjusting the orientation of thedisplay section 315, it is unnecessary to vary the orientation of theprobe 20. This contributes to quick detection of radiation.

Fifth Embodiment

A radiation detector 1 d according to a fifth embodiment will now bedescribed with reference to FIG. 12. FIG. 12 is a perspective viewshowing the radiation detector 1 d. The radiation detector 1 d has adisplay section 350 which can move independently of the head 2 and themain body 3. The display section 350 is placed on the side wall of theintermediate portion 310. The display section 350 is designed in aplanar shape, and fixed to the intermediate portion 310 via a hinge 70.Accordingly, the display section 350 is able to swing around an axiswith respect to the remaining portion of the intermediate portion 310.The user can erect the display section 350 from the main body 3 asnecessary. The user can adjust the orientation of the display section350 without varying the angle of the probe 20 or the intermediateportion 310 so that the display section 350 is easily viewable. Thiscontributes to quick detection of radiation. Since the side wall of theintermediate portion 310 exists under the display section 350, thesealing of the detector 1 d is maintained when the display section 350is moved.

Sixth Embodiment

A radiation detector 1 e according to a sixth embodiment will now bedescribed with reference to FIG. 13. FIG. 13 is a perspective viewshowing the radiation detector 1 e. The radiation detector 1 e has thedisplay section 351 capable of moving independently of both the head 2and the main body 3. The display section 351 is placed on the side wallof the grip 32. The display section 351 is designed to have a planarshape, and fixed to the grip 32 via the hinge 71. Accordingly, thedisplay section 351 is able to swing around an axis with respect to theremaining portion of the grip 32. The user can erect the display section351 from the grip 32 as necessary. The user can adjust the orientationof the display section 351 without varying the angle of the probe 20 orthe intermediate portion 310 so that the display section 351 is easilyviewable. This contributes to quick detection of radiation. Since theside wall of the grip 32 exists under the display section 351, thesealing of the detector 1 e is maintained when the display section 351is moved.

The present invention has been described in detail on the basis of theembodiments thereof. However, the present invention is not limited tothe above embodiments. Various modifications may be made to the presentinvention without departing from the gist thereof.

In the above embodiments, the articulation 4 for enabling the probe 20to swing is used as the moving mechanism for the head 2. However, othermoving mechanisms may be used. For example, a ball joint mechanism asshown in FIG. 14 may be provided on the head 2. The ball joint typearticulation 4 a has a probe fixing member 410 and holding members 411and 412. The probe fixing member 410 has a ball portion 410 a and acylindrical portion 410 b projecting from the ball portion 410. Athrough hole 410 c for wiring is formed in the ball portion 410 a. Thecylindrical portion 410 b has a connection pipe screw 220 accommodatedtherein. A female screw is formed in the inner surface of thecylindrical portion 410 b so as to be engaged with the connection pipescrew 220. The holding members 411 and 412 have hollow portions 411 aand 412 a for accommodating the ball portion 410 a therein, and throughholes 411 b and 412 b for wiring. Screw holes are formed in the rear endfaces of the holding members 411 and 412.

A support member 418 is fixed to the rear end surfaces of the holdingmembers 411 and 412 via the O ring 419. The O ring 419 is disposed in anannular groove 418 a formed in the front end face of the support member418. The O ring 419 is sandwiched between the rear end faces of theholding members 411 and 412 and the front end face of the support member418, thereby sealing the articulation 4 a. The support member 418 has athrough hole 418 b for wiring. A lead wire connected to the radiationdetection element 203 passes through the through hole 410 c of the probefixing member 410, the through holes 411 b and 412 b of the holdingmembers 411 and 412 and the through holes 418 b of the support member418.

The support member 418 is fixed to the intermediate portion 310, wherebythe articulation 4 a and the probe 20 are connected to the main body 3.Since the articulation 4 a is of a ball joint type, the probe 20 is ableto swing along various directions. Therefore, the orientation of theprobe 20 can be easily adjusted.

The combination of the above articulations 4, 4 a, 5 and 6 are notlimited to those of the above embodiments, and any combination may beadopted.

INDUSTRIAL APPLICABILITY

As described above, the radiation detector of the present invention hasthe second articulation in the head or the main body or therebetween inaddition to the first articulation for enabling the probe to move, sothat the ease of operation thereof is improved. Accordingly, using theradiation detector of the present invention makes it possible to quicklydetect radiation. Particularly, when the second articulation enables thehead to rotate, the probe can be very easily aimed at the desired placeto be examined. Furthermore, when the second articulation is connectedto the display section so that the display section is movable, the probecan be aimed at the desired place to be examined with maintaining thedisplay section at the easily visible position. This makes it easier todetect the radiation.

Thus the present invention can provide a radiation detector havingimproved ease of operation.

1. A radiation detector comprising: a main body, the main bodycomprising a grip; a head coupled to an end of the main body, the headcomprising a probe containing a radiation detection element, the mainbody comprising an intermediate portion coupled between the grip and thehead; a first articulation coupling the probe and another portion of thehead and enabling the probe to move with respect to the other portion ofthe head; and a second articulation coupling the intermediate portionand the grip and enabling the intermediate portion to swing with respectto the grip.
 2. The radiation detector according to claim 1, wherein thesecond articulation enables the head to move with respect to the grip.3. The radiation detector according to claim 1, wherein a thirdarticulation is provided between the head and the main body and enablesthe probe and the first articulation to rotate around a longitudinalaxis of the intermediate portion.
 4. The radiation detector according toclaim 3, further comprising a display section provided on the main body;and a fourth articulation connected to the display section, the fourtharticulation enabling the display section to rotate around alongitudinal axis of the intermediate portion with respect to the headand the grip.
 5. The radiation detector according to claim 4, wherein atleast the first, second and third articulations are sealed.
 6. Theradiation detector according to claim 3, wherein the first, second andthird articulations are sealed.
 7. The radiation detector according toclaim 1, further comprising a display section provided on the main body,wherein the second articulation is coupled to the display section toenable the display section to move.
 8. The radiation detector accordingto claim 7, wherein a third articulation enables the display section torotate around a longitudinal axis of the intermediate portion withrespect to the head and the grip.
 9. The radiation detector according toclaim 7, wherein the display section is movable independently of theremaining portion of the main body.
 10. The radiation detector accordingto claim 9, wherein the display section is able to swing with respect tothe remaining portion of the main body.
 11. The radiation detectoraccording to claim 1, wherein the first articulation enables the probeto swing with respect to the other portion of the head.
 12. Theradiation detector according to claim 11, wherein the first articulationenables the probe to swing around a first axis and the secondarticulation enables the intermediate portion to swing around a secondaxis that is parallel to the first axis.
 13. The radiation detectoraccording to claim 1, wherein the radiation detection element has adetection face for receiving radiation and generating an electricaloutput in response to incidence of radiation on the detection face, andwherein the probe further has a collimating opening extending from anend of the probe to the detection face and collimating radiationincident on the detection face.
 14. The radiation detector according toclaim 1, wherein the first and second articulations are sealed.
 15. Theradiation detector according to claim 1, wherein the main body includesa display screen and the first articulation is configured to enable theprobe to swing with respect to the other portion of the head around anaxis substantially perpendicular with respect to the longitudinal axisof the intermediate portion and substantially parallel with respect tothe display screen.
 16. The radiation detector according to claim 1,wherein the probe has a smooth, indentation-free surface.
 17. Theradiation detector according to claim 1, where the probe has a crosssection at its distal end away from the main body of the radiationdetector that is not larger than the cross section of the probe at itsproximal end adjacent the main body of the radiation detector.
 18. Theradiation detector according to claim 1, where the intermediate portionhas a cross section at its distal end away from the grip of the mainbody of the radiation detector that is not larger than the cross sectionof the intermediate portion at its proximal end adjacent the grip of themain body of the radiation detector.